1. Field of the Invention
The present invention relates to an edge grinding apparatus and method for grinding a glass substrate, and more particularly, to an edge grinding apparatus and method for grinding a glass substrate, with which a glass substrate can be ground by a fixed amount and the occurrence of defects can be minimized.
2. Description of Related Art
In general, glass substrates for flat panel displays, such as plasma display panels (PDPs) or liquid crystal displays (LCDs), are used after having been machined to a predetermined size and shape.
Specifically, glass substrates undergo a machining process, which is generally divided into cutting, grinding and cleaning. In the machining process, the grinding process is performed such that the cut edge of a glass substrate cut in the cutting process is ground and is then polished using a grinding wheel.
In the current process of machining a glass substrate, the grinding process is performed by moving the glass substrate when the grinding wheel is fixed. Here, if the size of the glass substrate changes, it is misaligned before being ground, or the straightness of a grinding table which transports it while holding it via suction, changes, the grinding wheel grinds it by a greater or less amount than the fixed amount. This causes defects, such as insufficient grinding, burning, and fracturing, during this grinding process. In addition, this causes the edge of the glass substrate to fracture during post-processing, such as cleaning, inspection, and packing.
Here, the problem is that it is difficult to properly compensate for variation, such as changes in the size of the glass substrate, alignment mismatches, and changes in the straightness of the grinding table, in case that the grinding wheel is fixed. In an example, although the size of the glass substrate and the straightness of the grinding table must not vary over time once they have been mechanically set to an accurate value, variation from several to tens of micrometers occurs, depending on the processing conditions. In addition, the alignment of the glass substrate on the grinding table before grinding the glass substrate results in an error of tens of micrometers, since the aligning need to mechanically push four edges of the glass substrate.
Accordingly, in the related art, the amount by which a glass substrate is ground is not set to a fixed value because of the defects occurring due to the foregoing phenomena, and thus the amount of grinding must be frequently adjusted during the manufacture of the glass substrate.
The information disclosed in this Background of the Invention section is only for the enhancement of understanding of the background of the invention, and should not be taken as an acknowledgment or any form of suggestion that this information forms a prior art that would already be known to a person skilled in the art.